A sound absorption material is a material having a strong performance of absorbing acoustic energy and reducing noise. When the sound absorption material is placed in a cavity, and a cavity is filled with sound pressure, the sound absorption material placed in the cavity absorbs partial acoustic energy, and this is equivalent to expanding a capacity of the cavity. Since the sound absorption material has such expansion characteristic, technician in the acoustic field place the sound absorption material in the cavities of some acoustic products to expand the capacity of the cavities of products without increasing external volume of the products, to improve the performance of acoustic products.
There are many kinds of materials capable of absorbing sound, but not every kind of sound absorption material has a very good expansion performance. To this end, technicians selects and uses a sound absorption material adapted for technical requirements of acoustic products from diverse sound absorption materials. However, currently there is not a device and a method for testing impedance characteristic and expansion performance of a sound absorption material. Technicians can only install each kind of sound absorption material into the acoustic product, then test to see whether the performance of the acoustic product changes or not, and thereby judge which sound absorption material is most adapted for the acoustic product. Such method of testing the sound absorption material is rather backward, causes large waste of manpower and material resources to enterprises, prolongs a development cycle of products, and thereby increases production costs of products.
In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.